Cahill, a 2006 A's second-round draft pick, pitched for Oakland from 2009-11. He started 96 games in three seasons with the A's, going 40-35 with a 3.91 ERA and 1.32 WHIP. Since Oakland traded him to the Arizona Diamondbacks in Dec. 2011, Cahill's pitched for six teams.

The 30-year-old won a World Series ring with the Chicago Cubs in 2016, and pitched for the San Diego Padres and Kansas City Royals last season. In 2017, he went 4-3 in 21 appearances (14 starts) with a 4.93 ERA and 1.62 WHIP.

Cotton, 26, went 9-10 with a 5.58 ERA in 2017 after a rookie season in which he went 2-0 with a 2.15 ERA in five starts. Leading up to the injury, he was 0-1 with a 3.75 ERA over four appearances in spring training.